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Abstract Marine heatwaves (MHWs) are projected to increase in intensity and frequency over the coming decades, and it is imperative to assess the adaptive capacity of marine organisms to these extreme temperature events. Given the nature of MHWs to last days to weeks in a region, these events may have overarching impacts on phenological events like reproduction and development. Here, the role of adult thermal history and transgenerational plasticity may be an important pathway by which MHWs are transduced to impact community structure. In this study, we sought to explore the effects of paternal thermal history in the purple urchin,Strongylocentrotus purpuratus, on a crucial aspect of reproduction, fertilization. Using ecologically relevant temperatures representative of both MHW events that occurred in 2014–2020 and non-MHW temperatures in our region of the California Large Marine Ecosystem, we conditioned maleS. purpuratusfor 28 days to either a high, MHW or a low, non-MHW temperature. Following the temperature acclimation of adults, sperm performance was tested for individual males by conducting fertilization success trials at varying temperatures and sperm concentrations. While sperm appeared robust to elevated temperature during fertilization, sperm produced by high-temperature-acclimated males had overall diminished performance as compared to those acclimated to non-MHW temperatures. These results suggest MHW events will have a negative impact on fertilization in situ forS. purpuratuspopulations. Furthermore, these results highlight the importance of considering both male and female environmental history in projections of reproduction under climate change scenarios.
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Thermal suppression of gametogenesis can explain historical collapses in larval recruitment
Abstract Projections for population viability under climate change are often made using estimates of thermal lethal thresholds. These estimates vary across life history stages and can be valuable for explaining or forecasting shifts in population viability. However, sublethal temperatures can also depress vital rates and shape fluctuations in the reproductive viability of populations. For example, heatwaves may suppress reproduction, leading to recruitment failure before lethal temperatures are reached. Despite a growing awareness of this issue, tying sublethal effects to observed recruitment failure remains a challenge especially in marine environments. We experimentally show that sublethal suppression of female gametogenesis by marine heatwaves can partially explain historical collapses in urchin recruitment. These responses differ by sex but are similar between animals from warmer or cooler regions of their range. Overall, we show sublethal thermal sensitivities of reproduction can narrow the thermal envelope for population viability compared to predictions from lethal limits.
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- Award ID(s):
- 2023664
- PAR ID:
- 10566130
- Editor(s):
- Inglis, John; Sever, Richard
- Publisher / Repository:
- bioRxiv
- Date Published:
- Edition / Version:
- 1
- Volume:
- 59
- Issue:
- 1
- Page Range / eLocation ID:
- 1-29.
- Subject(s) / Keyword(s):
- Sea urchin Strongylocentrotus reproduction invertebrates marine heatwave
- Format(s):
- Medium: X Size: 2MB Other: pdfA
- Size(s):
- 2MB
- Institution:
- bioRxiv
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Posted Content:
- https://doi.org/10.1101/2023.09.28.559919
